METHOD AND APPARATUS FOR DETECTION OF DEFECTS USING LOCALIZED HEAT INJECTION OF SHORT LASER PULSES

摘要

A method for inspecting an object and detecting defects is taught ( BGA and Flip-Chip solder joints on a PCB particularly). The method comprises injecting a heat pulse by light beam at a selected point on the object; capturing a sequence of consecutive thermal images of the object to record heat diffusion over time resulting from the heat pulse; comparing the heat diffusion over time at the point on said object to a reference; and determining whether the object comprises any defects. An apparatus for performing the described method is also described.